We saw a still earlier this week, but this NASA visualization video is truly awesome. It shows how aerosols—fine particles suspended in air—travel around the world in a van Gogh-ish dance of color. This is what you are seeing here:

The visualization—made with a climate model by NASA Goddard's Global Modeling and Assimilation Office—goes from August 2006 to April 2007. According to NASA, "such simulations allow scientists to better understand how these tiny particulates travel in the atmosphere and influence weather and climate." [NASA/Goddard Space Flight Center]